Many applications exist where an interface separates two fluids having different properties. It is often necessary to provide a seal at the interface to prevent mixing of the fluids or the transfer of one fluid into a volume occupied by a second fluid. Typically, seals may take the form of compression seals at abutting surfaces, wipers at sliding surfaces and gland-type seals for concentric surfaces.
Compression seals between abutting surfaces are frequently used where the abutting surfaces must be assembled and disassembled. However, the abutting surfaces compressing the seal generally have manufacturing tolerances which effect the parallelism between the surfaces. Further, the structures forming the abutting surfaces may not always be axially aligned so that, again, the surfaces are not parallel. Frequently, both of these conditions exist, requiring that the compression seal accommodate a range of displacements between the abutting surfaces.
Typically, a pressure differential exists across the interface and the seal must exert sufficient sealing force to overcome the forcing effect of the differential pressure. The sealing force is a function of the elasticity of the sealing material, the seal dimensions and the actual displacement to be occupied by the seal. No sealing exists where the displacement is greater than the seal dimensions can occupy. On the other hand, seal removal and installation will be increasingly difficult as seal compression requirements increase.
Thus, it would be desirable for a seal or gasket to retain sealing capability over a wide range of adjoining surface displacements while permitting the surfaces to be assembled or disassembled with a minimum effort. These, and other problems in the prior art, are overcome by the present invention wherein an improved gasket provides a compression seal including both a wiper seal configuration and an axial compression seal configuration.